The present invention is generally related to the field of mechanical receiver tuners, and is more specifically related to the field of mechanical tuners for tuning radio receivers.
Typically, in manual mechanically tunable radio receivers, mechanical vibrations of the receiver result in tuning "microphonics" which are generally defined as undesired tuning perturbations due to the mechanical vibrations causing undesired movement of mechanically movable tuning elements which determine the tuning of the radio receiver by determining the magnitude of associated impedances (reactances or resistances) in accordance with the mechanical position of the tuning elements. The elimination of such tuning microphonics has been a long standing problem in the mechanically tunable radio receiver art and most solutions involve providing shock protection for the mechanically movable elements or increasing the friction coefficient between the movable tuning elements and their surroundings. These solutions have generally proved to be unsatisfactory since they are either too costly or they undesirably increase the actuation force required to initially tune the radio to desired stations by desired movement of the mechanically movable tuning elements.
All electronic radio tuners have been implemented through the use of complex and costly frequency synthesizers. While these electronic tuners have substantially eliminated the microphonics problems of the prior mechanical tuners, they require a number of additional costly electronic circuits and are generally not as easily adjusted and convenient to set as the prior mechanical tuners.